package com.data_structure_algorithm.data_structure.stack.operationstack;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Stack;
import java.util.regex.Pattern;

public class ReversePolishMultiCalc {

  /**
   * 匹配 + - * / ( ) 运算符
   */
  static final String SYMBOL = "\\+|-|\\*|/|\\(|\\)";

  static final String LEFT = "(";
  static final String RIGHT = ")";
  static final String ADD = "+";
  static final String MINUS= "-";
  static final String TIMES = "*";
  static final String DIVISION = "/";

  /**
   * 加減 + -
   */
  static final int LEVEL_01 = 1;
  /**
   * 乘除 * /
   */
  static final int LEVEL_02 = 2;

  /**
   * 括号
   */
  static final int LEVEL_HIGH = Integer.MAX_VALUE;


  static Stack<String> stack = new Stack< String>();
  static List<String> data = Collections.synchronizedList(new ArrayList<String>());

  /**
   * 去除所有空白符
   * @param s
   * @return
   */
  public static String replaceAllBlank(String s ){
    // \\s+ 匹配任何空白字符，包括空格、制表符、换页符等等, 等价于[ \f\n\r\t\v]
    return s.replaceAll("\\s+","");
  }

  /**
   * 判断是不是数字 int double long float
   * @param s
   * @return
   */
  public static boolean isNumber(String s){
    Pattern pattern = Pattern.compile("^[-\\+]?[.\\d]*$");
    return pattern.matcher(s).matches();
  }

  /**
   * 判断是不是运算符
   * @param s
   * @return
   */
  public static boolean isSymbol(String s){
    return s.matches(SYMBOL);
  }

  /**
   * 匹配运算等级
   * @param s
   * @return
   */
  public static int calcLevel(String s){
    if("+".equals(s) || "-".equals(s)){
      return LEVEL_01;
    } else if("*".equals(s) || "/".equals(s)){
      return LEVEL_02;
    }
    return LEVEL_HIGH;
  }

  /**
   * 匹配
   * @param s
   * @throws Exception
   */
  public static List<String> doMatch (String s) throws Exception{
    if(s == null || "".equals(s.trim())) throw new RuntimeException("data is empty");
    if(!isNumber(s.charAt(0)+"")) throw new RuntimeException("data illeagle,start not with a number");

    s = replaceAllBlank(s);

    String each;
    int start = 0;

    for (int i = 0; i < s.length(); i++) {
      if(isSymbol(s.charAt(i)+"")){
        each = s.charAt(i)+"";
        //栈为空，(操作符，或者 操作符优先级大于栈顶优先级 && 操作符优先级不是( )的优先级 及是 ) 不能直接入栈
        if(stack.isEmpty() || LEFT.equals(each)
            || ((calcLevel(each) > calcLevel(stack.peek())) && calcLevel(each) < LEVEL_HIGH)){
          stack.push(each);
        }else if( !stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek())){
          //栈非空，操作符优先级小于等于栈顶优先级时出栈入列，直到栈为空，或者遇到了(，最后操作符入栈
          while (!stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek()) ){
            if(calcLevel(stack.peek()) == LEVEL_HIGH){
              break;
            }
            data.add(stack.pop());
          }
          stack.push(each);
        }else if(RIGHT.equals(each)){
          // ) 操作符，依次出栈入列直到空栈或者遇到了第一个)操作符，此时)出栈
          while (!stack.isEmpty() && LEVEL_HIGH >= calcLevel(stack.peek())){
            if(LEVEL_HIGH == calcLevel(stack.peek())){
              stack.pop();
              break;
            }
            data.add(stack.pop());
          }
        }
        start = i ;    //前一个运算符的位置
      }else if( i == s.length()-1 || isSymbol(s.charAt(i+1)+"") ){
        each = start == 0 ? s.substring(start,i+1) : s.substring(start+1,i+1);
        if(isNumber(each)) {
          data.add(each);
          continue;
        }
        throw new RuntimeException("data not match number");
      }
    }
    //如果栈里还有元素，此时元素需要依次出栈入列，可以想象栈里剩下栈顶为/，栈底为+，应该依次出栈入列，可以直接翻转整个stack 添加到队列
    Collections.reverse(stack);
    data.addAll(new ArrayList<String>(stack));

    //System.out.println(data);
    return data;
  }

  /**
   * 算出结果
   * @param list
   * @return
   */
  public static Double doCalc(List<String> list){
    Double d = 0d;
    if(list == null || list.isEmpty()){
      return null;
    }
    if (list.size() == 1){
      //System.out.println(list);
      d = Double.valueOf(list.get(0));
      return d;
    }
    ArrayList<String> list1 = new ArrayList<String>();
    for (int i = 0; i < list.size(); i++) {
      list1.add(list.get(i));
      if(isSymbol(list.get(i))){
        Double d1 = doTheMath(list.get(i - 2), list.get(i - 1), list.get(i));
        list1.remove(i);
        list1.remove(i-1);
        list1.set(i-2,d1+"");
        list1.addAll(list.subList(i+1,list.size()));
        break;
      }
    }
    d = doCalc(list1);
    //System.out.println(aDouble);
    return d;
  }

  /**
   * 运算
   * @param s1
   * @param s2
   * @param symbol
   * @return
   */
  public static Double doTheMath(String s1,String s2,String symbol){
    Double result ;
    switch (symbol){
      case ADD : result = Double.valueOf(s1) + Double.valueOf(s2); break;
      case MINUS : result = Double.valueOf(s1) - Double.valueOf(s2); break;
      case TIMES : result = Double.valueOf(s1) * Double.valueOf(s2); break;
      case DIVISION : result = Double.valueOf(s1) / Double.valueOf(s2); break;
      default : result = null;
    }
    return result;

  }

  public static void main(String[] args) {
    //String math = "9+(3-1)*3+10/2";
    String math = "12.8 + (2 - 3.55)*4+10/5.0";
    try {
      Double result = doCalc(doMatch(math));
      System.out.println(result);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}
